The present invention refers to a floor transport system with rail-mounted floor transport vehicles.
Typically, floor transport vehicles travel along slotted rail channels having built-in current conductors for providing electrical power. Each vehicle includes a guide mechanism and a current collector mechanism and at least one drive unit for traveling on a rail system made from guide rails which are recessed in the floor or ground plane and manufactured from an abrasion-resistant material. The rail system has a slotted track path for guiding the floor transport vehicles, and at least two current conductors for supplying power. The floor transport vehicles are moveable on at least two running wheels and have guide elements sliding in the slotted track channel of the guide rail as well as current collector shoes which interact with at least one drive unit rotatably mounted in the forward area of the vehicle frame about a vertical steering axis and including at least one drive wheel driven by a motor.
Floor transport systems of this type are disclosed e.g. in German Pat. No. 25 42 682 A1, European Pat. Nos. 0 151 982 A3 and 0 616 933 A1. Conventional floor transport systems with floor transport vehicles of this type are mainly used inside buildings, preferably in manufacturing and storage facilities, for transporting, for example, larger workpieces or bulky goods. Further applications of such transport systems with floor transport vehicles include assembly lines in the manufacture of e.g. motor vehicles. The rails with the current conductors are recessed, but flush with the floor level, so that the wheels of vehicles which are not restricted to rails, e.g. bicycles, can run across the rails without being thrown off balance or getting bumped.
With the more widespread use of floor transport systems of this type, there is a need to satisfy the requirements of different applications. Some conventional systems are not optimally suited for special or difficult applications. In some applications, vehicles have to be able to move in both directions. For in hauling material over short distances between successive automatic or manual machining operations, in particular with heavy workpieces, it can be troublesome if the drive wheel(s) traverse(s) the slotted track channel at a very acute angle. The rubber tires of the drive wheels can then be severely deformed by the edges of the slotted track channel, and especially the current conductors and the material in which the slotted track channel and the current conductors are embedded, can be damaged if, for example, foreign objects are pressed into the material. Moreover, dirt can impair the functionality of the current conductors.